With the development of the internet, cloud services that combine the server and the internet together have become widely used in recent years, so the amount of the data that the server needs to process grows at a remarkable speed. This causes a high demand for a server having larger storage space and faster write/read speed. In order to accommodate more storage units in the server, assemblies in the serve usually are disposed in the casing side by side and densely.
However, because assemblies in the server usually are disposed in the casing side by side and densely, some disks in the disk assemblies are interfered by other assemblies when the disks need to be changed or repaired. In this way, the user needs to remove the whole disk assembly from the casing or to move other assemblies away to repair or change the disks. Therefore, the efficiency and the convenience for the user to maintain the disks are deteriorated.